/Engine/Source/Editor/UnrealEd/Public/Subsystems/AssetEditorSubsystem.h
Creates a scriptable editor mode based on ID name, which will be owned by the given Owner, if that name exists in the map of editor modes found at system startup.
A pointer to the createdUEdModeor nullptr, if the given ModeID does not exist in the set of known modes.
[UEdMode](API\Editor\UnrealEd\Tools\UEdMode) * CreateEditorModeWithToolsOwner ( FEditorModeID ModeID, [FEditorModeTools](API\Editor\UnrealEd\FEditorModeTools) & Owner )